The NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE) has documented a high prevalence of coronary vascular dysfunction in women with symptoms and evidence of ischemia with no obstructive CAD. The condition is associated with an adverse prognosis and healthcare costs similar to obstructive CAD, there are an estimated 2-3 million women with existent disease, and a projected 100,000 new cases annually. This places the prevalence, morbidity and costs of coronary vascular dysfunction higher than all female reproductive cancers combined. Prospective testing of a noninvasive approach for diagnosis and prognosis is needed as critical next steps toward translation of our findings into clinical care. Using a prospective cohort design with follow-up, we aim to investigate: 1) Abnormal cardiac magnetic resonance imaging (CMRI) predicts abnormalities in coronary reactivity testing (CRT); 2) Persistent cardiac magnetic resonance imaging (CMRI) abnormalities at 1-year follow-up predict persistent symptoms of ischemia; 3) CMRI predicts adverse outcomes, and thus can be used as an outcome in future therapeutic trials. The baseline study visit will include a physical exam and elicitation of medical history, symptoms, lifestyle and functional characteristics, and psychosocial status. We will recruit 375 women undergoing coronary angiography for suspected ischemia with no obstructive CAD. All 375 will undergo baseline CMRI imaging, and a subgroup of 200 will undergo repeat one-year follow-up CMRI. An additional subgroup of 200 women with no coronary stenosis >20% in any epicardial coronary artery will undergo CRT. Women will be contacted annually to measure outcome of symptoms, coronary events, and associated costs. Established WISE core laboratories and clinical sites will be used. Documentation of the link between invasive CRT and noninvasive CMRI imaging, and the prognostic value of this measure for symptoms and adverse outcomes, will provide a platform for clinical trials to test therapeutic interventions in appropriately powered studies. Potential therapeutic trials being planned include anti-ischemia therapies, such as ranolazine and dipyridamole, as well as novel interventions, such as erythropoietin and stem-cell therapy, targeting coronary vascular function. Results of the application will provide practicing physicians with the ability to translate these findings to clinical care to improve IHD outcomes in women using a noninvasive assessment strategy.